Electrostatic precipitator cell for desk or tabletop air purifier

ABSTRACT

An electronic air purifier having the ionizing chamber and the collecting plates all formed into an integral cell which may be easily removed from the main housing of a desk or tabletop air purifier for cleaning, repair or replacement.

0 United States Patent 1151 3,678,655 Rose 1 July 25, 1972 541 ELECTROSTATIC PRECIPITATOR 2,675,091 4/1954 Brixius et al ..55/128 CELL FOR DESK OR TABLETOP AIR 2,665,770 1/1954 Richardson ..55/145 x PURIFIER 2,696,893 12/1954 Richardson... .....55/138 x 2,873,000 2/1959 Elam ..55/139 x [72] g f g 2:5 1237 5 PM 3,040,498 6/1962 Berly ..55/139 x 3,073,094 1/1963 Landgrafet al ..55/156 x 122 Filed: June 3,1969

Primary Examiner-Dennis E. Talbert Jr. 4 [21] Appl No 8299 3 Attorney-Thomas G. Devine 52 us. c1 ..55/128, 55/138, 55/145, [57] ABSTRACT 55/146, 55/148, 55/151 [51] Int. Cl. 803C 3/38, An l onic air p rifier having the ionizing chamber and the [58] Field 61 Search ..55/156, 128, 129, 130, 131, collecting plates all formed into an integral which y be 55/136, 138, 143, 145, 146, 151, 149, 148 easily removed from the main housing ofa desk or tabletop air purifier for cleaning, repair or replacement. [56] References Cited 6 Claims, 4 Drawing Figures Patented July 25, 1972 "m. m v "HUI l3 INVENTOR RONALD /V. FUSE BY ATTO NEYS ELECTROSTATIC PRECIPITATOR CELL FOR DESK OR TABLETOP AIR PURIFIER CROSS REFERENCE TO RELATED APPLICATIONS This application is related to US. Design application D- 15429 by the same inventor, filed .Ian. 21, 1969, now US. Design Pat. No. 216,592 granted Feb. 17, 1970.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is directed for use in the field of electrostatic air cleaning devices. This invention is particularly directed toward domestic air purifiers, as differentiated from industrial devices, where ease of cleaning or replacing the collector plates is particularly important.

2. Description of the Prior Art Through the years, there have been a number of electrostatic air purifiers which operate on the principle of charging the particles of impurities carried by the air in an ionizing chamber and then sending the charged particles into a collecting chamber where they are drawn to and deposited on collecting plates having suitable electrical potentials. Because of the great amount of air pollution today in urban areas, (which appears to be continuously increasing) air purifiers of this na ture have become more prominent and useful in the widely used living areas, such as homes and offices. Despite efforts by government and industry to control air pollution, there is still a great amount of pollution being carried into homes and offices and which should be removed from the air for the health and comfort of the inhabitants. In the electronic precipitator type of air cleaner the collecting plates become covered with the collected particles so that they must be cleaned or, if disposable, be discarded and replaced with new plates from time to time. In this invention the air cleaner is provided with a unitary precipitator cell in which the ionizing chamber and the collecting plates are all part of one integral unit which can be easily removed from or inserted into the main housing for cleaning or discarding and replacing the plates or for repairs that might be necessary.

SUMMARY An electronic air purifier is provided with a single or unitary precipitator cell in which the ionizing chamber and collecting plates are formed together as an integral unit and which is located in a manner and at a position where it may be readily removed and reinserted into the housing. The precipitator cell is located and constructed in a manner such that all of the air drawn into the air cleaner housing passes through the cell chamber to ensure that all the air goes through the ionizing chamber and past the collecting plates. Preferably, the precipitator cell is located where it can be conveniently removed from and reinserted back into the air cleaner by the average household user so that it can be cleaned or replaced quickly and easily.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a front view of the housing of an electronic air purifier suitable for containing a precipitator cell constructed according to the teachings of this invention;

FIG. 2 is a side sectional view of the housing taken along viewing line 2-2 of FIG. 1;

FIG. 3 is a partial break away perspective view of an embodiment of the invention in a form suitable for use in the housing illustrated in FIGS. 1 and 2; and

FIG. 4 is a side sectional view of the embodiment illustrated in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT The electronic precipitator of this invention operates in the same manner and according to the same principles as other well-known electrostatic precipitators. The air containing contaminating particles is drawn into an ionizing chamber in which a relatively high-potential electrostatic field is produced, usually by a wire or a group of wires which are electrically connected to some high potential energy source. A number, if not all, of the impurities carried by the air are ionized or charged electrically in the ionizing chamber and are carried by the moving air past a set of plates which are electrically charged to attract the ionized particles thereby removing them from the air flow. The air then continues out through a passageway devoid of a considerable amount of pollutant. As is well known, for best cleaning efficiency, the precipitator must be designed so that the ionizing area, the number and size of collection plates, ionizing potentials, etc., must all be adequately selected with respect to the rate of air flow and other factors. These are matters which persons experienced in the field of design of electrostatic air purifiers are able to decide and select based upon knowledge and experience so need not be described nor explained here in any detail.

Turning now to the present invention, the housing for a typical domestic air purifier 10 which is particularly suitable for home or ofi'ice use, is usually box shaped having a front, two sides, back, top and bottom. In the embodiment illustrated in FIG. 1, no limitation thereto being intended, the air inlet 11 is located in front of the housing and the outlet 12 is located in the bottom towards the rear of the housing The air is drawn into the housing through inlet 11 and driven out of the housing through outlet 12 by a fan 13 which is located just above the outlet opening. The fan is electrically powered by a suitable energy source (not shown) and is selected to pull the air through the precipitator at a rate commensurate with the cleaning capabilities of the precipitator.

The outer shell 16 of precipitator cell 15 is made from a sheet of electrically conductive material which is curved back on itself to form a cross section U, as can be most clearly seen in FIG. 4. The outer shell can be said to form an imperforate top plate member 16a, an imperforate bottom plate member 16b, and a perforated curved portion 16c. The perforations are a multitude of tiny openings covering approximately 50 percent of the curved portion area. The left and right sides of the outer shell 16 are closed off by side wall members 17 which are made out of a relatively stiff, non-conductive material such as some form of suitable plastic. The edges of the outer shell 16 may be embedded in the walls 17 or may be fitted into grooves or slots formed on the inside of the wall member 17 or can be attached to the walls in any convenient fashion. In any event, the wall members joined with the outer shell 16 form a chamber so that air which is drawn into the chamber through the perforated area 16c can only pass through the chamber and leave through the opening at the back end.

Within the precipitator cell chamber, extending from right to left and located approximately at the radius of curvature of the curved portion is an ionizing wire 18. As is the usual practice, there is applied to ionizing wire 18 (from a source and through means not shown) a relatively high ionizing potential which produces an electrostatic field all around the wire. Dust and other impurity particles carried by the air which passes into the precipitator cell chamber through the perforations in the curved area 160 all come within the influence of the electrostatic field developed by ionizing wire 18. Most of the particles, if not all, pick up an electrical charge so they then constitute ions which are carried out of the ionizing area rearward through the precipitator cell chamber toward the outlet opening. Located rearward from the ionizing wire 18 within the chamber and arranged parallel to the top and bottom plate members 16a and 16b, are inner plate members 19, 20 and 21 which are all made from some relatively stiff, electrically conductive material. The illustrated embodiment uses three inner plates but no limitation thereto is intended since the number of plates is a matter of choice and design. The inner plates 19, 20 and 21 are evenly spaced from each other and from plates 16a and I6b. The right and left edges of plates 19, 20 and 21 are held in place by wall members 17. Their edges may be firmly embedded in the wall members 17 or may be resting in slide grooves or slots on the inside of these walls. The latter arrangement may be preferable to facilitate cleaning of the collector plates or removing and replacing them if they are of the disposable type.

The center plate 20 is, by means not shown, held at the same general electrical potential level as the outer plates 16a and 16b. Preferably, this is at electrical ground. Intermediate plates 19 and 21 are preferably at the same electrical potential level as the ionizing wire 18. As illustrated in FIG. 4, the ionizing wire 18 is mechanically and electrically attached to plate 21 or plate 19 by a support member 23. Means (not shown) are provided to connect the various members in the electrostatic precipitator cell 15 to the proper electrical energy sources or potential levels. Ordinarily this would be by means of electrical contacts or connectors at the rear of or on the sides of the cell assembly. Typically, with no limitation thereto intended, ionizing wire 18 may be in the order of 2 mills diameter and be at a potential level of 4,800 volts positive. The outer plate members 16a and 16b and center plate 20 are ordinarily negative with respect to the ionizing wire 18 and preferably are at ground potential. The intermediate plates 19 and 21 may be at the same potential as the ionizing wire or may be somewhat less but yet are considerably more positive than the outer and center plates. Typical dimensions of a precipitator cell in an air purifier for table top or desk top use which has operated very satisfactorily are: the outer plate members 16a and 16b spaced approximately 1 inch apart with V4 inch spacing between adjacent plates within the cell chamber; plates in the order of 9 k inches wide, with outer plates [6a and 16b being in the order of 3 1% inches deep with the inner plates being in the order of 2 15 inches deep. These dimensions, of course, are only intended to be illustrative and not limitive.

The air purifier operates in the usual manner. After the electrostatic precipitator cell 15 has been inserted into the input slot in housing 10, the sources for the ionizing potential and fan 13 are energized. Air is drawn into the cleaner through the perforated area 160 and the particles of impurities carried by the air are subjected to the ionizing effect of the ionizing wire 18. As the charged particles are carried by the air rearward through the precipitator cell chamber, they are attracted to plates 16a, 16b and 20 and are repelled by the intermediate plates 19 and 21. It has been found that some particles do come to rest on the intermediate plates 19 and 21. This might come about because the other collector plates may loosen their hold on some of the particles and when they leave they are no longer charged positively so may be attracted to the intermediate plates. The air, without the pollutants which have been deposited on the plates, continues through the chamber out the open back end and through the outlet opening 12. From time to time, the collector plates must be cleaned to remove the particles which have gathered on it and this is readily achieved merely by sliding the precipitator cell assembly 15 out through the inlet opening 11 and cleaning the plates off in some suitable fashion and then reinserting the cell in the inlet slot. in some instances, the inner plates, 19, 20 and 21, may be disposable so they can be slipped out of the chamber and replaced with clean fresh plates and then the entire cell assembly reinserted into the housing 10. Of course, the entire cell assembly may be a disposable unit so it may be removed, discarded and replaced with a new one.

along their side edges by non-conductive wall members forming a chamber through which the incoming air passes;

c. a set of imperforate, electrically-conductive inner plates located within said chamber parallel to said outer plate members, said inner plates being engaged with said wall members along their side edges, and being spaced apart to permit air flow between them;

d. an ionizing wire within said chamber stretched across said chamber in the inlet area; and

e. means for attaching said ionizing wire to at least one of the inner plates.

2. The invention as set forth in claim 1 wherein said outer plate members and the perforated curved section are all one sheet of material.

3. The invention as set forth in claim 1 wherein said set of inner plates comprises an odd number of at least three plates.

4. The invention as in claim 1 wherein said wall members are adapted for slidable mounting in the precipitator housing whereby the precipitator cell can be removed from or inserted into the housing.

5. The invention as set forth in claim 4 wherein the perforated portion extends at least part way out of the inlet opening in the housing and the cell is slidably mounted in said inlet.

6. An electrostatic precipitator comprising, in combination:

a. a housing having an inlet passageway and an outlet passageway through which air passes;

b. means for drawing air into and forcing it out of said housing through said passageways;

c. an integral precipitator cell for ionizing and collecting particles in the air, said cell being slidably mounted in said housing in said inlet passageway;

d. said cell comprising:

i. a sheet of electrically conductive material bent to form an elongated U in cross-section with the curved portion being perforated and the leg portions being imperforate, the perforated section located at the opening of the inlet passageway so the incoming air passes therethrough;

ii. rigid non-conductive side wall members attached to the side edges of said sheet closing off said sides to form a chamber through which the air passes;

iii. a number of spaced apart conductive plates within said chamber attached to said wall members, said plates being parallel to and spaced from the imperforate sections of said first sheet; and

iv. an ionizing wire stretching from side to side within said chamber located adjacent the perforated section of said first sheet and connected to at least one of the conductive plates. 

1. In an electrostatic precipitator having a housing containing an inlet for receiving air and an outlet for discharging air, a precipitator cell for inserting into said housing comprising in combination: a. a pair of outer parallel, imperforate, electricallyconductive, plate members joined together along their front edges by a perforated curved portion, said perforated portion adapted to be located at the inlet of the precipitator so that air entering the housing passes therethrough; b. said outer plate members being spaced apart and held along their side edges by non-conductive wall members forming a chamber through which the incoming air passes; c. a set of imperforate, electrically-conductive inner plates located within said chamber parallel to said outer plate members, said inner plates being engaged with said wall members along their side edges, and being spaced apart to permit air flow between them; d. an ionizing wire within said chamber stretched across said chamber in the inlet area; and e. means for attaching said ionizing wire to at least one of the inner plates.
 2. The invention as set forth in claim 1 wherein said outer plate members and the perforated curved section are all one sheet of material.
 3. The invention as set forth in claim 1 wherein said set of inner plates comprises an odd number of at least three plates.
 4. The invention as in claim 1 wherein said wall members are adapted for slidable mounting in the precipitator housing whereby the precipitator cell can be removed from or inserted into the housing.
 5. The invention as set forth in claim 4 wherein the perforated portion extends at least part way out of the inlet opening in the housing and the cell is slidably mounted in said inlet.
 6. An electrostatic precipitator comprising, in combination: a. a housing having an inlet passageway and an outlet passageway through which air passes; b. means for drawing air into and forcing it out of said housing through said passageways; c. an integral precipitator cell for ionizing and collecting particles in the air, said cell being slidably mounted in said housing in said inlet passageway; d. said cell comprising: i. a sheet of electrically conductive material bent to form an elongated U in cross-section with the curved portion being perforated and the leg portions being imperforate, the perforated section located at the opening of the inlet passageway so the incoming air passes therethrough; ii. rigid non-conductive side wall members attached to the side edges of said sheet closing off said sides to form a chamber through which the air passes; iii. a number of spaced apart conductive plates within said chamber attached to said wall members, said plates being parallel to and spaced from the imperforate sections of said first sheet; and iv. an ionizing wire stretching from side to side within said chamber located adjacent the perforated section of said first sheet and connected to at least one of the conductive plates. 